Cuff pressure measurement device for a tracheal tube

ABSTRACT

According to various embodiments, methods and systems for determining pressure in an inflatable cuff of a tracheal tube may employ pressure transducers associated with a cuff inflation line or a pilot balloon assembly. The pressure transducers may be implemented to provide continuous or intermittent cuff pressure. Also provided are tracheal tubes with adapters or other devices that incorporate pressure transducers. The tracheal tubes may facilitate wireless cuff pressure monitoring.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/461,292 filed May 1, 2012, the contents of which are herebyincorporated by reference in their entirety.

BACKGROUND

The present disclosure relates generally to medical devices and, moreparticularly, to airway devices, such as tracheal tubes.

This section is intended to introduce the reader to aspects of the artthat may be related to various aspects of the present disclosure, whichare described and/or claimed below. This discussion is believed to behelpful in providing the reader with background information tofacilitate a better understanding of the various aspects of the presentdisclosure. Accordingly, it should be understood that these statementsare to be read in this light, and not as admissions of prior art.

In the course of treating a patient, a tube or other medical device maybe used to control the flow of air, food, fluids, or other substancesinto the patient. For example, tracheal tubes may be used to control theflow of air or other gases through a patient's trachea and into thelungs, for example during patient ventilation. Such tracheal tubes mayinclude endotracheal (ET) tubes, tracheotomy tubes, or transtrachealtubes. In many instances, it is desirable to provide a seal between theoutside of the tube or device and the interior of the passage in whichthe tube or device is inserted. In this way, substances can only flowthrough the passage via the tube or other medical device, allowing amedical practitioner to maintain control over the type and amount ofsubstances flowing into and out of the patient.

To seal these types of tracheal tubes, an inflatable cuff may beassociated with the tubes. When inflated, the cuff generally expandsinto the surrounding trachea (or, in the case of laryngeal masks, overthe trachea) to seal the tracheal passage around the tube to facilitatethe controlled delivery of gases via a medical device (e.g., through thetube). As many patients are intubated for several days, healthcareworkers may need to balance achieving a high-quality tracheal seal withpossible patient discomfort. For example, if improperly overinflated,the pressure and/or frictional force of certain types of inflated cuffsagainst the tracheal walls may result in some tracheal tissue damage.While a cuff may be inflated at lower pressure to avoid such damage,this may lower the quality of the cuff's seal against the trachea. Lowcuff inflation pressures may also be associated with allowing folds toform in the walls of the cuff that may serve as leak paths for air aswell as microbe-laden secretions.

Additionally, the quality of a cuff's seal against the trachealpassageway may suffer over the duration of a patient's intubation time.For example, a seal may be compromised when a patient coughs, which maydislodge the cuff from a sealed position. Further, when the trachealtube is jostled during patient transport or medical procedures, theforce of the movement may shift the position of the inflatable cuffwithin the trachea, allowing gaps to form between the cuff and thetracheal walls. Accordingly, it may be desirable to monitor the internalpressure in the cuff to determine if the cuff is properly inflated.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the disclosure may become apparent upon reading thefollowing detailed description and upon reference to the drawings inwhich:

FIG. 1 illustrates a system including a tracheal tube with a pressuretransducer for monitoring cuff pressure according to embodiments of thepresent techniques;

FIG. 2 is a perspective view of an endotracheal tube that may be used inconjunction with the system of FIG. 1;

FIG. 3 is a perspective view of an endotracheal tube with a pilotballoon assembly including a pressure transducer that may be used inconjunction with the system of FIG. 1;

FIG. 4 is a perspective view of a pilot balloon assembly including aproximal adapter with a pressure transducer;

FIG. 5 is a perspective view of a pilot balloon assembly including apressure transducer incorporated into a balloon wall;

FIG. 6 is a perspective view of a pilot balloon assembly including apressure transducer that forms a side of the pilot balloon;

FIG. 7 is a side view of a pilot balloon assembly of FIG. 6;

FIG. 8 is a perspective view of an endotracheal tube with an inflationline and an in-line adapter including pressure transducer that may beused in conjunction with the system of FIG. 1; and

FIG. 9 is a side view of an example of an in-line adapter including apressure transducer.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

One or more specific embodiments of the present disclosure will bedescribed below. In an effort to provide a concise description of theseembodiments, not all features of an actual implementation are describedin the specification. It should be appreciated that in the developmentof any such actual implementation, as in any engineering or designproject, numerous implementation-specific decisions must be made toachieve the developers' specific goals, such as compliance withsystem-related and business-related constraints, which may vary from oneimplementation to another. Moreover, it should be appreciated that sucha development effort might be complex and time consuming, but wouldnevertheless be a routine undertaking of design, fabrication, andmanufacture for those of ordinary skill having the benefit of thisdisclosure.

A tracheal tube may be used to seal a patient's airway and providepositive pressure to the lungs when properly inserted into a patient'strachea. A high quality seal of a cuff against the tracheal walls mayassist in isolating the lower airway and anchoring the tube in place.However, a conforming seal is often difficult to obtain over long-termintubation. Physicians may attempt to determine the quality of a cuffseal by monitoring inflation pressure via devices such as manometersthat are temporarily attached to the exposed valve of the cuff inflationline. However, these devices are generally used intermittently for spotchecks of cuff pressure and, therefore, add to the workflow ofclinicians. Further, the devices include connecting tubes to transfergas from the cuff inflation line to pressure sensors. When the devicesare disconnected, the air transferred to the devices is lost to thesystem. Accordingly, each measurement results in an overall decrease incuff pressure, which may influence the integrity of the cuff seal. Othertechniques may involve a qualitative assessment of the stiffness of apilot balloon associated with the exposed end of the cuff inflationline. However, the pilot balloon stiffness does not provide aquantitative measurement of cuff pressure.

Accordingly, the disclosed embodiments provide a more accurate methodand system for determining trachea pressure by obtaining a measurementof pressure with pressure transducers associated with the cuff inflationline or the pilot balloon assembly. Such pressure transducers mayinclude wireless sensors that are capable of communicating with apatient monitor. In particular embodiments, the pressure transducer mayinclude components that are exposed to the interior space of theinflation line system (e.g., including the fluid enclosed by the cuff,the inflation line, and any components in fluid communication the cuffand the inflation line) and components that are exposed to ambient air.In one embodiment, the pressure transducers may be associated with anadapter that is used in conjunction with an inflation line or pilotballoon assembly. For example, a pilot balloon assembly may typicallyterminate at a proximal end in a valve that opens to allow air to enteror leave the inflation line. As provided herein, an adapterincorporating the valve may include a pressure transducer that is influid communication with the pilot balloon and the inflation line. Suchan embodiment may provide manufacturing advantages because the trachealtube, inflation line, and pilot balloon are unchanged. In anotherembodiment, the pressure transducer may be embedded in or incorporatedinto a wall of the pilot balloon itself. In yet additional embodiments,a pressure transducer may be incorporated into the inflation line. Forexample, an in-line adapter may bridge two sections of inflation lineand provide a pressure transducer surface that is in fluid communicationwith the inflation line.

In certain embodiments, the disclosed tracheal tubes, systems, andmethods may be used in conjunction with any appropriate medical device,including a tracheal tube, a feeding tube, an endotracheal tube, atracheotomy tube, a double-lumen tracheal tube (e.g., an endobronchealtube), a circuit, an airway accessory, a connector, an adapter, afilter, a humidifier, a nebulizer, nasal cannula, or a supraglottalmask/tube. The present techniques may also be used to monitor anypatient benefiting from mechanical ventilation, e.g., positive pressureventilation.

FIG. 1 shows an exemplary tracheal tube system 10 that has been insertedinto the trachea of a patient. The system 10 includes a tracheal tube12, shown here as an endotracheal tube, with an inflatable balloon cuff14 that may be inflated via inflation line 18 to form a seal against thetracheal walls. The tracheal tube 12 may also include a pressuretransducer 20 that is in fluid communication with the cuff 14. Incertain embodiments, the pressure transducer 20 may be coupled to amedical device, such as a ventilator 22 or a monitor 30. The monitor 30and/or the ventilator 22 may be configured to monitor pressure in thecuff 14 and, in particular embodiments, the pressure in the trachealspace 24.

The system 10 may also include devices that facilitate positive pressureventilation of a patient, such as the ventilator 22, which may includeany ventilator, such as those available from Nellcor Puritan BennettLLC. The system may also include a monitor 30 that may be configured toimplement embodiments of the present disclosure to determine pressuresbased upon the pressure in the cuff 14 or another cuff. It should beunderstood that the monitor 30 may be a stand-alone device or may, inembodiments, be integrated into a single device with, for example, theventilator 22.

The monitor 30 may include processing circuitry, such as amicroprocessor 32 coupled to an internal bus 34 and a display 36. In anembodiment, the monitor 30 may be configured to communicate with thetube, for example via the pressure transducer 20 or an associatedantenna, to obtain signals from the pressure transducer 20. In certainembodiments, the communication may also provide calibration informationfor the tube 12. The information may then be stored in mass storagedevice 40, such as RAM, PROM, optical storage devices, flash memorydevices, hardware storage devices, magnetic storage devices, or anysuitable computer-readable storage medium. The information may beaccessed and operated upon according to microprocessor 32 instructionsand stored executable instructions. In certain embodiments, calibrationinformation may be used in calculations for estimating of pressure inthe cuff based on measurements of pressure in the inflation line orassociated structures (e.g., the pilot balloon assembly). The monitor 30may be configured to provide indications of the cuff pressure, such asan audio, visual or other indication, or may be configured tocommunicate the estimated cuff pressure to another device, such as theventilator 22.

FIG. 2 is a perspective view of an exemplary tracheal tube 12 accordingto certain presently contemplated embodiments. It should be understoodthat the embodiments discussed herein may be implemented with anysuitable airway device including a cuff 14, such as a tracheal tube, anendotracheal tube, a tracheostomy tube, a laryngeal mask, etc. Further,the embodiments disclosed herein may be used with any medical devicethat includes an inflatable component that is inflated via an inflationline that may include a pilot balloon assembly. For example, the tube 12includes a cuff 14 inflated via inflation lumen 18, which terminates inan opening 46 that is located within the inflated interior space 48 ofthe cuff 14. The interior space 48 is fluid communication with thepressure transducer 20. The tracheal tube 14 is inserted in the patientsuch that the distal end 50 and the cuff 14 are positioned within thetrachea (see FIG. 1) and the proximal end 52 is located outside of thepatient for connection via connector 54 to a ventilator. The inflationlumen 18 includes an interior portion 60 and an exterior portion 62 thatextends away from the wall 64 of the tube 12 at an opening 66.

The pressure transducer 20 may be any suitable pressure sensor, such asa piezoelectric pressure sensor. In one embodiment, the pressure sensormay incorporate a passive or active RFID circuit that may be readwirelessly to convey pressure monitoring information and/or calibrationor identification information to the monitor 30. In particularembodiments, a passive RFID component without power connections orbattery components may be advantageous. The monitor 30 may incorporatean RFID readout device. In one embodiment, the pressure transducer 20may be part of an assembly that includes a capacitor type pressuresensor and a tuned antenna for a resonance frequency in a medical band,such as a frequency in the 2.450 GHz center frequency or the 5.800 GHzband (or higher). The sensor may be a CMUT (capacitive micromachinedultrasonic transducer) sensor with a movable membrane fabricated onto asilicon chip of a size suitable for the embodiments discussed herein. Incertain embodiments, a sweep of the transmission frequency measures theresonant frequency of the pressure transducer 20, which is a function ofthe cuff pressure. The pressure transducer 20 may be capable of sensingpressures in a range of 0 to 50 cm of H₂0.

The pressure transducer 20 may also be associated with an informationelement, such as a memory circuit, such as an EPROM, EEPROM, codedresistor, or flash memory device for storing calibration information forthe pressure transducer 20. The pressure transducer 20 may also be partof an assembly that contains certain processing circuitry for at leastpartially processing signals from the pressure transducer 20 or forinteracting with any memory circuitry provided. When the pressuretransducer 20 communicates with the monitor 30, the information elementmay be accessed to provide calibration information to the monitor 30. Incertain embodiments, the calibration information may be provided in abarcode that may be scanned by a reader coupled to the monitor 30.Alternatively, the pressure transducer 20 may include a passive oractive RFID circuit that may be read wirelessly to convey pressuremonitoring information and cuff calibration information to the monitor30.

The tube 12 and the cuff 14 are formed from materials having suitablemechanical properties (such as puncture resistance, pin hole resistance,tensile strength), chemical properties (such as biocompatibility). Inone embodiment, the walls of the cuff 14 are made of a polyurethanehaving suitable mechanical and chemical properties. An example of asuitable polyurethane is Dow Pellethane® 2363-80A. In anotherembodiment, the walls of the cuff 14 are made of a suitable polyvinylchloride (PVC). In certain embodiments, the cuff 14 may be generallysized and shaped as a high volume, low pressure cuff that may bedesigned to be inflated to pressures between about 15 cm H₂O and 30 cmH₂O. However, it should be understood that the intracuff pressure may bedynamic. Accordingly, the initial inflation pressure of the cuff 14 maychange over time or may change with changes in the seal quality or theposition of the cuff 14 within the trachea.

The system 10 may also include a respiratory circuit (not shown)connected to the endotracheal tube 12 that allows one-way flow ofexpired gases away from the patient and one-way flow of inspired gasestowards the patient. The respiratory circuit, including the tube 12, mayinclude standard medical tubing made from suitable materials such aspolyurethane, polyvinyl chloride (PVC), polyethylene teraphthalate(PETP), low-density polyethylene (LDPE), polypropylene, silicone,neoprene, polytetrafluoroethylene (PTFE), or polyisoprene.

FIG. 3 illustrates a tracheal tube 12 including a pilot balloon assembly72 at the proximal end 70 of the inflation line 18. In particularembodiments (see FIGS. 4-7), the pressure transducer 20 may beassociated with the pilot balloon assembly 72, which may include a pilotballoon 74 configured to be in fluid communication with the interiorspace 48 of the cuff 14. The pilot balloon is coupled to the proximalend 70 of the inflation line at a distal pilot balloon end 76. In thedepicted embodiment, the proximal pilot balloon end 78 is coupled to avalve 80. The valve 80 is configured to open to allow the transfer offluid in or out of the inflation system to inflate or deflate the cuff14. For example, the valve 80 may be configured to accommodate aninflation syringe. In one implementation, insertion of the syringe maydepress a spring-loaded plunger, which opens the valve 80. Removal ofthe syringe allows the plunger to return to a closed configuration ofthe valve 80. It should be understood that other configurations of avalve may also be incorporated into the pilot balloon assembly 72.

In certain embodiments, the pressure transducer 20 may be associatedwith an adapter assembly 90 configured to be inserted into openingformed in the pilot balloon 74 as shown in FIG. 4. In such anembodiment, a distal end 92 of the adapter assembly 90 may be configuredto couple to an opening formed in the proximal pilot balloon end 78. Abarb 94 or other retention feature may retain the adapter assembly 90 onthe pilot balloon 74 through an interference fit with the proximal pilotballoon end 78. The adapter assembly 90 may be removable or, inembodiments, may be adhered to the pilot balloon 74. For example, inother embodiments, the adapter assembly 90 may be adhered to, welded,heat bonded, or overmolded to the pilot balloon assembly 72. A proximalopening 96 of the adapter assembly 90 is coupled to a valve 98. Thevalve 98 may operate in a manner similar to valve 80, allowing inflationor deflation of the cuff 14 via a syringe. Accordingly, a tube 12 withthe adapter assembly 90 includes an integral cuff pressure transducerand is capable of cuff inflation via a syringe. The depicted arrangementmay provide certain advantages over Y-type connectors that have separatebranches to connect to a syringe and a pressure measurement device. Byproviding a single connection for a syringe (and no connection for apressure transducer 20, which is integral to the adapter assembly 90),any confusion about which connector to use is eliminated. Further, theadapter assembly 90 may be used in conjunction with a standard pilotballoon 74 and inflation line 18, keeping the same capability ofqualitative assessment of the cuff pressure by the clinician throughsqueezing the pilot balloon.

The adapter assembly 90 may define an enclosed space 100 that is influid communication with the interior of the pilot balloon 74 and may beformed from a rigid or conformable material that is substantiallyimpermeable to ambient air. The adapter assembly 90 may be any suitableshape, such as generally spherical or elliptical. Because the cuff 14may be inflated by transferring air from an inflation syringe (or otherfluid source) through the interior enclosed space 100, the adapterassembly is not dead space or does not result in an overall loss offluid from the cuff 14. Further, the inflation may be monitored via thepressure transducer 20 until a desired intracuff pressure is achieved.Fluid in the inflation system (represented by arrow 102) equilibrates toa constant pressure within the enclosed space 100, so that the measuredpressure in the adapter assembly 90 represents the intracuff pressure.

The pressure transducer 20 may be coupled to the adapter assembly sothat one surface is exposed to the ambient air and one surface isexposed to the enclosed space 100. The pressure transducer 20 mayinclude a flexible membrane with an electrode surface. The interiorpressure of the inflation system results in movement or deflection ofthe membrane and its electrode relative to a second electrode surface.The displacement generates an alternating signal that is related to thesize of the gap between the electrode surface, the amount ofdisplacement, and the thickness of the membrane. The pressure transducer20 may be fabricated so that the displacement amount within expectedcuff pressures is tuned to a particular frequency. The signal may becommunicated via antennas 104. In the depicted arrangement, the antennas104 are diametrically opposed to one another on an exterior surface ofthe adapter assembly 90. The pressure transducer 20 may be coupled tothe antennas 104, which are configured to communicate with the patientmonitor 30 in a selected band. The antennas 104 may be arranged withrespect to the adapter assembly 90 to facilitate wireless communicationat a desired distance or at multiple angles. For example, in oneembodiment, one or more antennas 104 form a spiral or curved shape aboutthe pressure transducer 20 and are disposed to increase overall surfacecoverage.

In an alternate arrangement, the pressure transducer 20 may be coupleddirectly to the pilot balloon 74. As shown in FIG. 5, the pressuretransducer 20 may be embedded in or otherwise formed within the pilotballoon wall 118. In one embodiment, the pilot balloon 74 may bemanufactured with openings formed to connect at the distal pilot balloonend 76 to the inflation line and at the proximal pilot balloon end 78 tothe valve 80. An opening in the balloon wall 118 may be cut toaccommodate the pressure transducer 20, and the pressure transducer 20may be positioned relative to the pilot balloon 74 such that theinterior surface 120 is within the enclosed space of the pilot balloonand the exterior surface 122 is exposed to ambient air. Antennas 104 aand 104 b may be wrapped about the exterior of the pilot balloon walls118.

FIG. 6 depicts an implementation in which the pressure transducer 20 isdisposed on a substrate 130. The substrate 130 may be rigid orconformable. In embodiments in which the substrate is rigid, the balloonwalls 118 remain conformable, which allows a clinician to feel thestiffness to estimate the cuff pressure. The substrate 130 may providemore surface area to attach to the balloon walls 118. For example, theballoon walls may be glued or otherwise adhered to an exterior surface132 of the substrate (or, in alternative implementation, to an interiorsurface 134). In certain embodiments, the substrate 130 may be atwo-part component that clips the balloon walls 118 to enclose theinterior of the pilot balloon 74.

The substrate 130 may also provide a surface for one or more antennas104. In the depicted arrangement, the antennas 104 a and 104 b (see FIG.7) are offset from one another on the exterior surface 132 to avoidinterference. In another embodiment, the antennas 104 a and 104 b may bearranged in concentric spirals about the pressure transducer 20.

The pressure transducer 20 may also be associated with the inflationline 18. FIG. 8 is a perspective view of the tracheal tube 12 includingan inflation line adapter 150 that is positioned in-line with theinflation line on the exterior portion 62. In such an arrangement, thepilot balloon assembly 72 may be formed according to conventionaltechniques. The inflation line adapter 150 connects or bridges aproximal portion 140 and a distal portion 142 of the inflation line 18.In one embodiment, the inflation line adapter 150 may be coupled to theinflation line 18 by cutting the inflation line 18 and inserting theinflation line adapter 150 between the two portions 140 and 142 thatwere previously adjacent to one another.

FIG. 9 is a side view of the inflation line adapter 150. The exteriorsurface 152 is sized and shaped to fit in-line with the portions 140 and142. The exterior surface 152 may be generally barrel-shaped. In oneembodiment, the exterior surface 152 defines a widest diameter d1 is atleast wider than the outer diameter d2 of the inflation line. Such anarrangement prevents the proximal portion 140 and the distal portion 142from being pushed towards one another to cover the exterior surface 120of the pressure transducer 20. The inflation line adapter 150 may beretained in place via barbed ends 154 and 156 and/or adhered to theinflation line 18. For example, in other embodiments, the inflation lineadapter 150 may be adhered to, welded, heat bonded, or overmolded to theinflation line 18. The barbed ends 154 and 156 are hollow so that fluid,represented by arrows 157, is capable of moving through an enclosedspace 158 and into the inflation line 18.

The antenna wires 164 a and 164 b may be soldered or otherwise coupledto the pressure transducer 20 and may run along the length of theinflation line 18 to the pressure transducer 20 in any suitable manner.For example, the antenna wires 164 may be embedded (e.g., via extrusion)within the wall 162 of the tube inflation line 18, may be run along theinside or the outside of the inflation line 18, or may be printed on theinflation line 18. In one embodiment, the antenna wires 164 embeddedwithin the wall 162 of the inflation line 18 are exposed by strippingaway a portion of the inflation line wall 162 to reveal the wires 164,which are soldered to the pressure transducer 20 and the coupling 170may be protected by epoxy.

In another embodiment, the pressure transducer 120 may be integratedinto a wall of the inflation line 18 such that at least a portion of thepressure transducer 120 is exposed to ambient air and a portion of thepressure transducer 120 is exposed to the interior of the inflation line18. The antenna wires 164 may soldered to the pressure transducer andthe coupling may be protected with epoxy.

While the disclosure may be susceptible to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and have been described in detail herein.However, it should be understood that the embodiments provided hereinare not intended to be limited to the particular forms disclosed.Indeed, the disclosed embodiments may not only be applied tomeasurements of cuff pressure, but these techniques may also be utilizedfor the measurement and/or analysis of the tracheal pressure based onmeasurements of cuff pressure. Rather, the various embodiments may coverall modifications, equivalents, and alternatives falling within thespirit and scope of the disclosure as defined by the following appendedclaims.

What is claimed is:
 1. A tracheal tube comprising: a conduit configuredto be inserted into a trachea of a subject; an inflatable cuff disposedon the conduit and configured to contact the trachea of the subject; aninflation line in fluid communication with the inflatable cuff; a pilotballoon associated with a proximal end of the inflation line; and apressure transducer associated with the pilot balloon and comprising aninterior surface exposed to an interior space of the pilot balloon andan exterior surface exposed to ambient air.
 2. The tracheal tube ofclaim 1, comprising an antenna coupled to the pressure transducer anddisposed about a wall of the pilot balloon.
 3. The tracheal tube ofclaim 1, wherein the pressure transducer is coupled to a wall of thepilot balloon.
 4. The tracheal tube of claim 1, wherein the pressuretransducer is disposed on a rigid substrate and wherein a wall of thepilot balloon is adhered to a surface of the rigid substrate.
 5. Thetracheal tube of claim 4, wherein the pressure transducer comprises amembrane.
 6. A tracheal tube comprising: a conduit configured to beinserted into a trachea of a subject; an inflatable cuff disposed on theconduit and configured to contact the trachea of the subject; aninflation line in fluid communication with the inflatable cuff; a pilotballoon associated with a proximal end of the inflation line; and anadapter coupled to the pilot balloon and comprising an interior surfacein fluid communication with an interior space of the pilot balloon; apressure transducer associated with the adapter and comprising aninterior surface in fluid communication with the interior space of thepilot balloon and an exterior surface exposed to ambient air; and avalve coupled to the adapter and configured to allow fluid to flowthrough the adapter and into the inflation line via the pilot balloonwhen open and to prevent fluid from entering the inflation line whenclosed.
 7. The tracheal tube of claim 6, comprising antennas disposed ondiametrically opposed surface of the adapter.
 8. The tracheal tube ofclaim 7, wherein the antennas form a spiral or curved shape about thepressure transducer.
 9. The tracheal tube of claim 6, wherein theexterior surface of the pressure transducer forms a part of a transducerside of the adapter.
 10. The tracheal tube of claim 9, comprising atleast one antenna disposed on the transducer side of the adapter. 11.The tracheal tube of claim 6, wherein the adapter is coupled to thepilot balloon at a distal end of the adapter and wherein the valve isoriented at a proximal end of the adapter.
 12. The tracheal tube ofclaim 6, wherein the adapter comprises a barbed end configured tocoupled the adapter to the pilot balloon.
 13. The tracheal tube of claim6, wherein the pressure transducer comprises a flexible membranecomprising an electrode surface.
 14. The tracheal tube of claim 6,wherein the adapter is removable.
 15. The tracheal tube of claim 6,wherein the adapter comprises a spherical or elliptical shape.
 17. Atracheal tube comprising, a conduit configured to be inserted into atrachea of a subject; an inflatable cuff disposed on the conduit andconfigured to contact the trachea of the subject; an inflation line influid communication with the inflatable cuff; a pilot balloon associatedwith a proximal end of the inflation line; and a pressure transducerassociated with the pilot balloon and disposed on a surface of asubstrate coupled to the pilot balloon.
 18. The tracheal tube of claim17, wherein the pilot balloon is coupled to an exterior surface of thesubstrate.
 19. The tracheal tube of claim 17, wherein the pilot balloonis coupled to an interior surface of the substrate.
 20. The trachealtube of claim 17, comprising antennas disposed on an exterior surface ofthe substrate.